1. Field of the Invention
The present invention relates to a disk drive command interface, and more particularly, to a disk drive for implementing data transfer initiated by optional disk-drive commands on a serial interface that only supports specific standard disk-drive commands.
2. Description of the Prior Art
A standard parallel ATA interface uses a 40-pin connector and a bulky flat ribbon cable that is becoming unable to accommodate further growth in the data transfer capacity of the interface. A serial ATA interface is emerging that can accommodate growth in data transfer capacity and that uses a significantly smaller 7 conductor connector. The connector includes a receive differential pair of conductors and a transmit differential pair of conductors. The remaining three conductors are ground connections. The serial ATA interface does not support nonstandard, optional, or vendor specific disk-drive commands. Typically, unsupported disk-drive commands are used primarily during disk-drive manufacture and quality testing. Providing a separate disk-drive command interface would add to the cost of the disk drive.
Additionally, the disk-drive command for a Small Computer System Interface (SCSI) may be transferred over a serial link such as serial ATA or Universal Serial Bus (USB). However, a serial attached SCSI (SAS) interface may not support nonstandard, optional, or vendor specific disk-drive commands.
Accordingly, there exists a need for a disk drive that implements data transfer initiated by unsupported disk-drive commands on a serial interface that only supports specific ATA disk-drive commands. The present invention satisfies theses needs.